The Scarborough Planning Board has told Cosco to plan for a dedicated right-turn lane into its proposed gas station, a rendering of which is shown here, to forestall potential traffic problems. Contributed / Costco

The Scarborough Planning Board keyed in on potential traffic problems at a gas station entrance as it continues to vet an application for what would be the state’s first Costco store.

The retail giant Monday addressed the board’s previous concern about the size of the parking lot on the proposed site at The Downs and its impact on abutting wetlands, and it asked for waivers to town ordinances on parking lot driving lanes and the height of light poles.

The Costco gas station proposed along Payne Road poses a traffic issue, board members said, because two lanes merge into one on that section of the road. A dedicated right-turn lane is needed, they said.

“I’m not going to be in favor of this entrance – not the project, but the entrance – without a turning lane there,” board member Richard DuPerre said.

Other board members agreed, noting that lines at the gas station could extend to Payne Road. Costco representatives said Monday that, on average, 102 customers come to the gas station every hour and spend an average of 3½ minutes per visit.

“I’ve done many gas stations with Costco,” said Mark Marchisano, director of development at Costco. “(Gas station attendants) are specifically trained to deal with making sure people understand how to get through the facility.”

Board members still insisted on adding a turning lane to the plans.

“My experience is that it is always better to engineer out a hazard than to rely on a human being for that,” said board member Jennifer Ladd. “That is a great secondary reinforcement, but we should be able to take care of this issue before it even gets to Payne Road.”

To remediate a previous issue planners voiced, local wetlands will be protected with landscaping buffers and by replenishing the wetlands via stormwater drainage, the latter of which, representatives say, was supported by the Maine Department of Environmental Protection.

Costco representatives requested waivers from the board to permit slightly smaller lanes between parking spaces and taller light poles in the parking lot. The town mandates driving lanes between spaces to be at least 25 feet wide and set light poles at a standard height of 20 feet. Costco’s site plan calls for 24-foot-wide lanes and 36½-foot light poles.

While Planning Board members said they have no problems with the requested waivers, they still need a reason why the light poles have to be 16½ feet higher.

“I would like to see what it would look like for a person driving down the road, or walking down, what it would look like between a 20-foot pole and your 36-foot pole,” said Rick Meinking, the board’s vice chairperson. “Our standard is 20-foot poles, you’re asking for a waiver; you need to demonstrate why you need that waiver.”

The board asked Costco representatives to present the need for a light-pole waiver and plans for a turning lane into the gas station the next time they meet.

Costco, a popular membership warehouse club, applied in January to build a 161,000-square-foot structure on a 19.25-acre lot at the corner of Payne and Scarborough Downs roads. The parking lot Costco proposed was the focus when the proposal was discussed in January and March, with concerns about whether the paved area could impact wetlands and if larger-than-average parking spaces are needed. Costco representatives say 749 oversized 10-by-20 foot parking spaces are the standard for Costco stores across the nation for reasons of safety and efficiency.

Board members said they are excited about the prospect of a Costco coming to Scarborough but need to do their due diligence.

“Let me just be clear that this body does not look at the nature of the organization that is before us,” said Chairperson Rachel Hendrickson.  “In other words, that’s not part of the ordinances. It could be a wonderful company; it could be a lousy company. What is before us is what this company is proposing.”